Most warehouses, manufacturing facilities and large retail stores have loading docks that provide a location for loading and unloading trucks and trailers (hereinafter "vehicles"). Loading docks typically include a raised platform and a dock opening positioned above the raised platform. The dock opening is formed by a dock wall having two vertical side portions extending upwardly from the platform, and a horizontal upper portion connecting the top of the side portions. A vehicle can be backed toward the dock opening until the back of the vehicle is abutting the platform. For example, a resilient bumper can be mounted on the face of the platform to provide a cushioned member for the vehicle to be backed against. The platform sometimes includes a dockleveler that provides a ramp between the platform and the bed of the vehicle to facilitate loading and unloading of the vehicle (e.g., by a fork-lift).
Many loading docks include dock seals that provide a seal between the dock wall and the back of the vehicle. For example, such dock seals can include side pads and a head pad mounted (e.g., using fasteners) against the side portions and upper portion of the dock wall, respectively. The pads are commonly made from a wear resistant fabric (e.g., vinyl-coated fabric) surrounding a resilient material (e.g., foam) that is compressed when the back of the vehicle is positioned against the loading dock. The compressed pads provide a barrier against the elements (e.g., wind, rain, and snow), thereby providing a comfortable working environment for the personnel working near the loading dock, and further provide a barrier against the loss of heat or cooling from inside the building.
It has been discovered that, while the above-described pads provide a good seal against the sides and top of the vehicle opening, the seal against the bottom of the vehicle opening is not always ideal. More specifically, since the above-described bumpers maintain a space between the dock wall and the vehicle, there is commonly a gap between the dock wall and the bottom of the vehicle opening on either side of the dock leveler. This gap can allow exchange of interior and exterior air, which can create an uncomfortable working environment and/or result in the loss of valuable climate-controlled air from the interior of the loading dock.
To solve this problem, portable dock seals have been used to block the above-described gap between the vehicle and the dock wall. The portable dock seal can be positioned within the undesired gap to block the exchange of interior and exterior air. Such prior art portable dock seals include a canvas, or similar material shell filled with sand, similar to a bean bag. The sand provides weight to the seal so that it will stay in place, and further makes the seal conform to various shapes to provide a good seal in a variety of positions.